Quoted from cpr9999:I assume the computer will change too?
Assuming the original is no longer made. I am sure OS changes, drivers, compiling code on new computer all has impacts to some level.
This is where a 'closed system' is to your advantage. Unlike a desktop/laptop... the system doesn't run anything you don't put into it. The system doesn't do anything other than you ask of it. Thus, as long as the requirements don't change, the system can keep doing what it does without having to change anything.
What the vendors have to consider is
1 - availability of the parts to keep building the product as long as they want
2 - availability of the parts to provide spares/service
3 - software support for any future needs or defect fixes
4 - headroom for future needs
#3 is less of an issue the more mature something is as change is less frequent and you hope it's polished by then. You also consider if its things you can 'fix yourself' or if you rely on others. Same with #4 - if your product is mature and understood, your requirements are less likely to change
For isolated embedded systems... change is low probability. Mainly what they want to avoid is getting stuck where they can't get new parts to keep the assembly line running and the availability of replacements (so again, you avoid being forced to swap before you want to)
The motherboard alien uses is quite old by computer standards (almost 8 years?) but is still available to order from the china vendor. I wouldn't be suprised if they simply push PC updates down the road as a future refresh as long as the vendor could give them a reasonable End of Sale forecast. Since it's a closed platform, and they have all the existing binaries... they can keep using old stuff.
If they didn't get reasonable pricing or availability forecast.. they'd change and be forced to face more extensive regression testing to ensure the new hardware didn't have any unexpected differences in behavior.
It's more of question of supply chain management and then being forced to face software work just to maintain compatibility. There are a lot of reasons to 'not rock the boat' if they don't have to...